(12x^2 - 12xy + 3y^2) - 10.(2x - y) + 8 

= 3(4x^2 - 4xy + y^2) - 10(2x - y) + 8 

= 3(2x - y)^2 - 10(2x - y) + 8 

= 3(2x - y)^2 - 10(2x - y) + 8 

= 3(2x - y)^2 - 6(2x - y) - 4(2x - y) + 8 

= 3(2x - y)(2x - y - 2) - 4(2x - y -2) 

= (2x - y -2)[3(2x - y) - 4] 

= (2x - y -2)(6x - 3y -4)

Ai k mk mk k lại

(12x^2 - 12xy + 3y^2) - 10.(2x - y) + 8 
= 3(4x^2 - 4xy + y^2) - 10(2x - y) + 8 
= 3(2x - y)^2 - 10(2x - y) + 8 
= 3(2x - y)^2 - 10(2x - y) + 8 
= 3(2x - y)^2 - 6(2x - y) - 4(2x - y) + 8 
= 3(2x - y)(2x - y - 2) - 4(2x - y -2) 
= (2x - y -2)[3(2x - y) - 4] 
= (2x - y -2)(6x - 3y -4)

Đề si thì phải 12x^2 - 12xy + 3y^2 

sai de

a: \(A=x^3y-12xy-x^2y\)

\(=xy\cdot x^2-xy\cdot12-xy\cdot x\)

\(=xy\left(x^2-x-12\right)\)

\(=xy\left(x^2-4x+3x-12\right)\)

\(=xy\left[x\left(x-4\right)+3\left(x-4\right)\right]\)

\(=xy\left(x-4\right)\left(x+3\right)\)

c: \(C=\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)-120\)

=(x+1)(x+4)(x+2)(x+3)-120

\(=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-120\)

\(=\left(x^2+5x\right)^2+10\left(x^2+5x\right)+24-120\)

\(=\left(x^2+5x\right)^2+10\left(x^2+5x\right)-96\)

\(=\left(x^2+5x+16\right)\left(x^2+5x-6\right)\)

\(=\left(x^2+5x+16\right)\left(x+6\right)\left(x-1\right)\)

d: \(D=x^5-x^4+x^2-1\)

\(=\left(x^5-x^4\right)+\left(x^2-1\right)\)

\(=x^4\left(x-1\right)+\left(x-1\right)\left(x+1\right)\)

\(=\left(x-1\right)\left(x^4+x+1\right)\)

Đặt năm câu ghép xác định chủ ngữ vị ngữ

3*(\(4x^2-4xy+y^2\))-10(2x-y)+8

3*(2x-y)^2-10(2x-y)+8

3*(2x-y)^2-6(2x-y)-4(2x-y)+8

3(2x-y)(2x-y-2)-4(2x-y-2)

(2x-y-2)(6x-3y-40

\(\left(12x^2-12xy+3y^2\right)-10\left(2x-y\right)+8\)

\(=\left(12x^2-6xy-6xy+3y^2\right)-10\left(2x-y\right)+8\)

\(=\left[6x\left(2x-y\right)-3y\left(2x-y\right)\right]-10\left(2x-y\right)+8\)

\(=\left(2x-y\right)\left(6x-3y\right)-10\left(2x-y\right)+8\)

\(=3\left(2x-y\right)^2-10\left(2x-y\right)+8\)

Đặt \(2x-y=a\), khi đó biểu thức có dạng:

\(3a^2-10a+8=3a^2-6a-4a+8\)

\(=3a\left(a-2\right)-4\left(a-2\right)=\left(a-2\right)\left(3a-4\right)\)

\(=\left(2x-y-2\right)\left(6x-3y-4\right).\)

1) \(x^2-y^2-2x-2y\)

\(=\left(x^2-y^2\right)-\left(2x+2y\right)\)

\(=\left(x+y\right)\left(x-y\right)-2\left(x+y\right)\)

\(=\left(x+y\right)\left(x-y-2\right)\)

2) \(3x^2-3y^2-2\left(x-y\right)^2\)

\(=3\left(x^2-y^2\right)-2\left(x-y\right)^2\)

\(=3\left(x-y\right)\left(x+y\right)-2\left(x-y\right)^2\)

\(=\left(x-y\right)\left[3\left(x+y\right)-2\left(x-y\right)\right]\)

\(=\left(x-y\right)\left(3x+3y-2x+2y\right)\)

\(=\left(x-y\right)\left(x+5y\right)\)

1) x² - y² - 2x - 2y

= (x² - y²) - (2x + 2y)

= (x - y)(x + y) - 2(x + y)

= (x + y)(x - y - 2)

2) 3x² - 3y² - 2(x - y)²

= (3x² - 3y²) - 2(x - y)²

= 3(x² - y²) - 2(x - y)²

= 3(x - y)(x + y) - 2(x - y)²

= (x - y)[3(x + y) - 2(x - y)]

= (x - y)(3x + 3y - 2x + 2y)

= (x - y)(x + 5y)

`x^2-y^2 -2x-2y`

`= (x^2-y^2) -(2x+2y)`

`=(x-y)(x+y) -2(x+y)`

`= (x+y) (x-y-2)`

__

`3x^2 -3y^2 -2(x-y)^2`

`= 3(x^2 -y^2) - 2(x-y)^2`

`=3(x-y)(x+y) -2(x-y)^2`

`= (x-y) (3x+3y -2x+2y)`

`=(x-y)( x+5y)`

a) \(A=x^2-2xy+y^2+3x-3y-4\)

\(=\left(x-y\right)^2-1+3x-3y-3\)

\(=\left(x-y-1\right)\left(x-y+1\right)+3\left(x-y-1\right)\)

\(=\left(x-y-1\right)\left(x-y+1+3\right)\)

\(=\left(x-y-1\right)\left(x-y+4\right)\)

\(a,x^3+xy-2y-8\)

\(=\left(x^3-8\right)+\left(xy-2y\right)\)

\(=\left(x-2\right)\left(x^2+4x+4\right)+y\left(x-2\right)\)

\(=\left(x-2\right)\left(x^2+4x+4+y\right)\)

\(b,8x^3-12xy+2x^2y-3y^2\)

\(=\left(8x^3+2x^2y\right)-\left(12xy+3y^2\right)\)

\(=2x^2\left(4x+y\right)-3y\left(4x+y\right)\)

\(=\left(2x^2-3y\right)\left(4x+y\right)\)

`4x^2-1`

`=(2x)^2-1`

`=(2x-1)(2x+1)`

`125x^3+1`

`=(5x)^3+1`

`=(5x+1)(25x^2-5x+1)`

`x^4+2x^2+1`

`=(x^2+1)^2`

`4x^2-12xy+y^2`

`=4x^2-12xy+9y^2-8y^2`

`=(2x-3y)^2-(2sqrt2y)^2`

`=(2x-2sqrt2y-3y)(2x+2sqrt2y-3y)`